Well casing hanger



C. C. BROWN ea. 12, H367 WELL CA3 ING HANG ER 4 Sheets-Sheet 1 Filed June 22, 1965 INVENTOR d 564% Dec. 12, 1957 g; C BROWN 3,35K48fi WELL CA5 I NG HANGER Filed June 22, 1965 4 Sheets Shee't INVENTOR 6/6660 d 566% Dec. 12, 1967 c 3, BROWN 3,357,486

WELL CAS ING HANGER Filed June 22, 1965 4 Sheets-$heet 5 INVENTOR 6666a 63 Zia/V W67 c. c. BROWN 3,357,4i85

WELL CASING HANGER Filed June 22, 1965 4 Sheets-Sheet INVENTOR. 6/6620 6 580% BY/QMW% United States Patent 3,357,486 WELL CASING HANGER Cicero C. Brown, Houston, Tex., assignor to Atlantic Richfield Company, a corporation of Pennsylvania Filed June 22, 1965, Ser. No. 465,945 11 (Jlaims. (Cl. 166-.6)

ABSTRACT OF TI-E DISCLOSURE The present invention is directed to a casing hanger assembly for hanging a casing string within a well head and setting a packing element in the annulus between the casing hanger and the well head by an hydraulically actuated setting tool. The setting tool includes a mechanical setting and releasing means.

This invention relates to an apparatus for use at offshore wells and pertains more particularly to a setting tool for hanging a casing in an underwater wellhead and setting a packer thereon to seal 01f between the casing and the wellhead after the casing has been cemented.

Copending application of C. C. Brown and C. E. Wakefield, Jr., Ser. No. 310,333, filed Sept. 20, 1963, now abandoned, discloses a setting tool that sets the casing packer by rotation after cementing. A continuation-inpart of that application, Ser. No. 432,160, filed Feb. 12, 1965, now Patent. No. 3,279,539, discloses a hydraulic setting tool that requires only the application of pressure to set the packer. Each of these apparatuses has certain advantages and disadvantages over the other. At times it is difiicult to rotate the running string to set a packer because the operation is conducted from a floating vessel which may not be perfectly aligned with the well bore on the ocean floor. In this case the hydraulic set version has an advantage as it does not require rotation but still retains the disadvantage of being dependent upon the seals of the apparatus.

It is therefore one object of this invention to combine both the hydraulic and mechanical set features, each of which may be utilized independent of each other.

It is also an object of my present invention to provide a novel casing hanger assembly for hanging a casing string in a wellhead afiixed to an underwater well.

It is a further object of the present invention to provide a releasable casing hanger tool assembly for hanging a casing string in an underwater well which hydraulically sets the packer around said casing and mechanically releases said tool.

Another object of this invention is to provide a novel anchoring means between the setting tool and a tubular member aifixed to an underwater well for applying hydraulic pressure to set the casing packer.

Still another object is to provide an anchoring means that is readily releasable by rotating the setting tool body between a setting tool and a mandrel aflixed to an underwater well for applying hydraulic pressure to set the casing packer.

Other objects and a more complete understanding of my present invention may be had by reference to the following specification taken in conjunction with the appended claims and the drawings, wherein:

FIG. 1 is a view, partly in section and partly in elevation, showing the casing hanger as it is carried in the hole by the setting tool and landed against the indexing shoulder in the casing head;

FIG. 2 is a view, partly in section and partly in elevation, showing the casinghanger packer set hydraulically;

FIG. 3 is a view, partly -in section and partly in elevation, showing the casing hanger packer set both hydraulically and mechanically;

FIG. 4 is a view, partly in section and partly in elevation, showing the setting tool released from the casing hanger;

FIG. 5 is a horizontal cross-sectional view taken on lines 55 of FIG. 1;

FIG. 6 is a horizontal cross-sectional view taken on lines 66 of FIG. 3;

FIG. 7 is a horizontal cross-sectional view taken on lines 7-7 of FIG. 3;

FIG. 8 is a horizontal cross-sectional view taken on lines 88 of FIG. 3;

FIG. 9 shows, partially in section, the setting tool removed from the casing string;

FIG. 10 shows, partially in section, an elevation of the present casing hanger mandrel and casing string hung in a drilling mandrel.

Referring to the drawings generally, my present invention involves generally a casing hanger assembly for hanging the casing string C within a wellhead H which may, for example, be the drilling head, and setting a casing hanger packer 94 by a combination of hydraulic and mechanical means after which the setting tool may be mechanically released from the casing and removed from the well.

FIG. 1 shows the setting tool 10 made up into the casing hanger l1, and the casing hanger is landed against shoulder 79 of the wellhead H. FIG. 1 shows the position of the apparatus just prior to conventionally cementing the casing C in the well by pumping cement through the running string 1) down through the casing C and back up between the annulus of casing C and the wellhead H. Thus, returns come back to the surface between the annulus of the running string D and the inside diameter of wellhead H. It is standard procedure to set a packer on the casing hanger to seal off between the casing string and the casing head after cementing. The assembly in FIG. 1 embodies apparatus for a novel means of setting the hanger packer by a combination of mechanical and hydraulic means.

The construction of the hanger 11 is best shown in FIG. 10 which shows the setting tool removed from the casing hanger mandrel. Setting tool 10 is shown in FIG. 9 separated from the hanger 11 for ease in differentiating its parts.

The body of the hanger 11 is a tubular body with an inside diameter 13 substantially the same as the casing run below. A threaded connector 12 is provided on the lower end of the body for attaching the casing string C thereto. Provided in the bore adjacent the upper end of the body is an acme type box thread 32 for the purpose of attaching the body to the setting tool. Provided a short distance below this thread is counterbore '15 which defines shoulder 16 at its termination. Shoulder 16 is provided as a stop for the next smaller casing (not shown) to he landed therein. Provided in the bore 15 of the tubu- .lar body is an annular groove 17 having inwardly inclined end walls 17a. This groove serves as a lock down stop for the next smaller size casing (not shown).

A stop shoulder (or lugs) 13 is provided on the outside diameter of the tubing hanger mandrel 11 for landing against shoulder 79 of the casing head. Below this shoulder is provided a plurality of spring loaded dogs 92 which lock below shoulder of the casing hanger mandrel. A reduced diameter surface 19 is formed on the upper end of the tubular support terminating at and defining shoulder 20 which provides a space to install a seal member 94. Header rings 21 and 22 are provided at the upper and lower ends of the seals and are shear pinned to the tubular body. A setting sleeve 23 is installed with its lower face bearing against the upper seal header ring 21. The upper end of the setting sleeve is counterbored to shoulder 26. A tubular member 27 is threaded within this counterbore to the tubular support with a left hand acme type thread. The upper end of this member has a clutch 28 (FIG. 3) to provide a means for rotating member 27. This member is initially installed with its lower face bearing against shoulder 26 of the setting sleeve. A cone mem ber 29 provided with a slip segment 30 for holding the setting sleeve in its lowermost position is cut into the inside diameter of the setting sleeve 23. Suitable seal means 95 is provided for sealing off between the setting sleeve23 and the tubing hanger mandrel 11.

The casing hanger assembly may have its seal 94 set.

in either of two ways. By the application of a force downward on the setting sleeve 23 the shear pin through the upper header ring 21 will be sheared and the header ring 21 will be forced axially downward compressing or extruding seal 94 causing it to seal between the wellhead H and the hanger body 11. By rotation of the tubular member 27 to the right, by a means hereinafter described, member 27 will be moved axially downward against shoulder 26 of the setting sleeve causing it also to move downward to compress the seal to sealing engagement between the wellhead H and the casing hanger 11.

The setting tool is constructed to carry out the two above setting means plus carry the casing string C and casing hanger mandrel 11 into the hole and land it in the wellhead H. The setting tool is attached to the casing hanger mandrel with a floating nut 31 which is splined to the setting tool body 33 for limited axial movement therewith. The outside diameter of the floating nut is threaded with a male acme type thread which is preferably left hand in order to allow right hand release of the setting tool from the casing hanger mandrel after the mandrel is hung. The floating nut 31 is threaded into the mating left hand box thread 32 cut in the upper bore of the casing hanger mandrel for this purpose. As the casing hanger 11 with the casing string C attached thereto are run into the well, the weight is supported on shoulder 34 of the setting tool body. As best viewed in FIG. 5, the splines 35 of the setting tool body 33 mate the groove in the floating nut 31 such that as the setting tool body 33 is rotated, the nut is rotated but allows axial movement between the two members. A male thread 36 is provided on the upper end of the setting tool body for attaching it to the setting means body 37 through a mating box thread 38 cut in the lower bore of the setting means body. When these threads are. made up, enough distance is left between the lower face 39 of the setting means body and the upper ends of the splines 35 to install bearing ring 40. Mating race ring grooves are provided at 41 in the lower face of the setting means body and at 42 in the upper face of the bearing ring and ball bearings ,43 are provided therebetween. The lower outside diameter of the bearing ring is beveled to mate a bevel on the upper end of the casing hanger body. The outside diameter and the bevel are grooved at 44 to prevent a fluid block of the assembly. The use of the bearing ring is to provide for an easy release of the floating nut 31 in that after the casing hanger is landed against shoulder 79, the weight of the running string can be slacked off on the bearing ring against the upper beveled shoulder of the casing hanger and this will remove the axial load from the threads of the floating nut so that it may be rotated easily.

The structure required to set the casing hanger is mounted on the lower end of the setting means body 37. Above flange 45 an acme left hand male thread 37a is provided and a floating nut 46 is mated thereon. As best shown in FIG. 7, the outside diameter of this nut is splined or grooved 46a and mates with lugs or splines 47a cut in the upper bore of actuating sleeve 47. The actuating sleeve 47 fits inside the upper bore of setting sleeve 23 and its lower end has lugs or clutch members 48 (see FIG. 9) that clutch with the matinglugs 27a of the tubular member 27. The lower end of the actuating sleeve is counterbored back to shoulder 49. This allows the counterbore to extend over the bearing ring 40 with the upper face of the bearing ring retaining the actuating sleeve on the setting tool assembly. The proper spacing of the floating nut 46 from shoulder 49 of the setting means body will allow the floating nut 31 to be released before the nut 46 is caused by the right hand rotation to abut shoulder 49 and begin rotating the actuating sleeve which being clutched tothe tubular member 27, screws it downward on the hanger body and sets the seal 49 through the setting sleeve 23. This arrangement facilitates assembly of the setting tool into the casing hanger in that the setting tool must be rotated to the left to screw the floating nut 31. into the box thread 32. Before starting assembly, the nut 46 is screwed downward so that when the nut 31 is made up, nut 46 will have room to travel upward before coming to its uppermost stop. The threads on nut 46 are left hand.

To provide for mounting the structure for the hydraulic setting means, a reduced diameter section 50 is provided above the thread 37a on the setting means body. A male thread 51 is provided on the upper end of the body 37 in order to attach collar 52. Collar 52 has a box thread 53 on its upper end for attaching to the running pipe D. The reduced diameter section 50 defines a shoulder 50a at which point a bearing 55 is provided. A hearing is also provided below the lower face of the collar 52. These bearings are provided to facilitate rotation of the body in reference to the hydraulic setting means to be mounted between these two bearings.

Mounted on the setting means body 37 and below hearing 54 and abutting it is the anchor body 56. A snap ring 70 is provided in a groove in the setting means body to retain the anchor body 56 against the bearings 54. Body 56 is provided with a flanged member 57 at its outer lower end for the purpose of retaining a T-head ring 58 mounted about the body 56. T -headed dogs 59 are fitted into the mating T-slots in the T-head ring..The dogs have an upwardly facing shoulder 60 provided on their outside diameter designed to catch in the annular groove 61 indexed into the wellhead H. The lower inside surface of the dogs is conically inclined to mate cone member 62 mounted about the setting means body 37 directly below the dogs. The cone member 62 is axially spaced with the dogs in the set position by a ring member or floating nut 63. Ring member 63 is attached to the setting means body by a suitable thread 64. The thread 64a is extended below the ring member to allow rotation of the ring member to a lower position to allow release of the dogs 59 and anchor member 56, as will hereinafter be explained.

Retainer ring 66 is screwed into the upper bore of the cone member to provide an indexing shoulder 65 to bear against the upper face of the ring member 63. The ring member 63 is splined to the bore of the cone member to prevent rotation between these two members, but will allow axial movement therebetween. FIG. 6 illustrates the spline arrangement. A flanged member 67 is screwed to the upper outside end of the anchor body to provide an abutment for springs 68 to bear against in order for their lower ends to urge resiliently against the upper face of the T-head member to force the dogs upon the cone to the set position of the dogs shown in FIGS. 1-3. The springs are provided with guides by installing cap screws 69 through the T-head member and screwed into the lower face of the flange member 67.

The purpose of the anchor assembly described above is to provide a means for anchoring the setting tool to the wellhead H in order to permit application of hydraulic force to the setting sleeve 23 to set the packing 94 of the casing hanger, as will be described below.

To provide a piston for the hydraulically setting packer 94, the lower outside diameter of the cone member is reduced at 71, A cylinder member 72 is provided over this reduced diameter. A suitable seal 73 is provided to seal off between the piston and the cylinder member. Another seal 74 is provided to seal off between the piston member and the setting means body. The cylinder is attached to the piston member by a shear pin 72a to prevent prema ture setting of the packing 4. A cylinder head member 75 is attached to the cylinder by a suitable thread 76 and the bore of this member is sealed off with the setting means body by a suitable seal 77. This construction defines a chamber 78 which is communicated to the bore of the setting means body by passage 91. Seal ring 80 is installed against the upper face of bearing 55 and is retained there by snap ring 81 fitted in a groove in the setting means body. This seal ring 80 seals olf with the cylinder 72 with a suitable seal 82, and by seal 83 with the setting means body. This arrangement defines another chamber at 84 which is communicated with the bore of the setting means body by passage 85. By providing chambers 78 and 84, a surge of pressure from the bore of the setting means body acting through passages 91 and 85 will not prematurely actuate the hydraulic setting means as the pressures will be equalized on both sides of the cylinder head member 75.

To provide a piston for the hydraulically setting packer vided in the bore of the setting means body between passages 91 and 85 and a ball 87 may be pumped to this shoulder, as shown in FIG. 2, and hydraulic pressure applied above the ball. This will cause the pressure to be directed to chamber 78 and acts against the upper area of the cylinder head 75 pushing it downward which shears pin 72a and actuates the hydraulic setting means.

The lower bore of the cylinder 72 is provided with a female thread to which is attached, by the means of a male thread, the setting sleeve abutment ring 79a. The outside diameter of this ring is substantially the same as the cylinder 72 and its inside diameter is substantially the same as the bore of the setting sleeve 23. The lower bore of the abutment ring 79a is counterbored to allow this member to slip over the outside diameter of the setting sleeve. Shoulder 93 stops against the top of the setting sleeve so that when the hydraulic pressure is applied on cylinder head member 75 the force acts longitudinally on the setting sleeve.

A swivel connection 87 is provided in the lower part of the setting tool body in order to attach extension member 88 upon which is mounted suitable seals 89 of any well known type, such as the swab cups shown, which serve to prevent fluid from flowing back through the annulus between the setting tool and the inside diameter of the casing hanger mandrel. When cementing, this arrangement allows the pumping of cement to the bottom of the casing and back up on the outside of the casing.

In the use of the apparatus shown in FIGS. l4, the apparatus in run into the hole as in FIG. 1 until the shoulder 13 of the casing hanger mandrel lands against shoulder 79 of the wellhead H. At this time the spring loaded hold down dogs 92 will latch against shoulder 90 of the wellhead preventing withdrawal of the hanger mandrel from the hole. Circulation may now be established to Wash the well bore preparatory to cementing, after whichkonventional cementing may be now completed by any of the accepted means now in use. When cement is in position and the cementing job completed, the casing hanger assembly will appear as in FIG. 1.

' During the cementing operation the hydraulic means of the casing hanger packer was not set prematurely by differentials pumping pressures since the pressure balancing chambers 78 and 84 are both in communication with the pumping differentials prior to sealing off of the bore of the setting tool, as hereinafter described.

When the cementing operation is completed, the packer 94 is set by dropping a ball 87 into the running pipe. The ball settles to its seal 86 provided in the setting tool body. Pressure is now applied through the running pipe to pressurize chamber 78 0f the setting tool through passages 91 of the setting means body. Pressure built up in chamber 78 will act upward against the piston 62 and cone member forcing it against the dogs 59 which are anchored against shoulder 60 in wellhead H. Once anchored, no further movement will occur in the piston member 62. Therefore, the pressure acts downward against the cylinder head member 75. This will cause this member 75 to move downward as will the cylinder 72 to which it is attached, which will shear pins 72a. Since the cylinder is abutted against the top of the setting tool through the abutment ring 79a, the setting sleeve will be moved downward compressing the seal 94 into sealing engagement between the wellhead H and the casing hanger mandrel 11. If pressure is now relieved, the setting sleeve is kept from rising back up releasing the seal because of the cone member 29 pressing the slip segment to bite into the casing hanger body. The assembly will now appear as shown in FIG. 2 in the set position.

When the setting sleeve 23 was driven downwardly to set the packer 94, the shoulder 26 of the setting sleeve 23 moved downward from the lower face of the tubular member 27. To avoid relying solely on the slips 30 to hold the packer set, the lower face of the tubular member 27 may be moved downward to bear against the setting sleeve to hold it in set position. This may be accomplished by rotating running string D to the right. The setting tool body will rotate in reference to the rest of the assembly because of the friction of the anchor means locked into its recess is transmitted to these other members that are attached thereto. Rotation of the setting tool body to the right causes the floating nut 31 to also rotate as these members are connected by splines. Rotation will then release the floating nut 31 from the casing hanger mandrel, Rotation will also cause nut 46 to travel downward towards shoulder 49, and when it reaches shoulder 49, the nut will start rotating with the body. When this occurs, the nut will rotate the actuating sleeve 47 because it is splined thereto at 460:. The rotation of the actuating sleeve causes it to rotate the tubular member 27 because it is clutched thereto. This will cause the tubular member 27 to be screwed downward upon its threads 24 until it is fast against shoulder 26. In this position the lower face of the tubular member 27 bears against shoulder 26 retaining the setting sleeve 23 in set position. This position can be seen in FIG. 3.

It will be seen in FIG. 3 that the rotation of the setting tool moves the nut 63 downward from hearing against shoulder 65. This was caused by the rotation of the body 10 and the left hand threaded connection between it and the nut, the nut being held from rotation by its splined connection 63a with the cone member. This will allow the cone to be peach-seeded away from the dog as the tool is now picked up allow the setting tool to be removed from the hole. This position is shown in FIG. 4. Thus, the packer may be set by my present casing hanger assembly, either mechanically or hydraulically, and the setting tool released mechanically.

Although my present invention has been described with a certain degree of particularity, the scope of the invention is not limited to the details set forth, but in the full breadth of the appended claims.

I claim:

1. In an underwater casing hanger assembly for hanging a casing string in a tubular member having a shoulder therein and afiixed to a formation underlying a body of water and wherein a casing hanger mandrel connectible to the upper end of said casing string is adapted to land on said shoulder and is of such a configuration that an annular path is defined between said mandrel and said tubular member, and wherein annular sealing means are provided between said mandrel and said member which are of a configuration that permits fluids to pass said seal before said seal is extruded in said annulus, the improvement comprising:

a setting tool having means thereon for extruding said sealing means in said annulus, and

said setting tool having means for anchoring said setting tool relative to said tubular member for applying a force ,onsaid seal to extrude said seal between said mandrel and said tubular member.

2. An underwater casing hanger assembly for hanging a casing string in a tubular member having a shoulder therein and aflixed to a formation underlying a body of water, comprising in combination:

a casing hanger mandrel connectible to the upper end of said casing string and arranged and constructed to land on said shoulder of said tubular member, said mandrel being of a configuration such that an annular path is defined between said mandrel and said tubular member through which path fluids can pass when said mandrel is landed on said shoulder,

extrudable sealing means arranged in said annulus be tween said mandrel and said tubular member whereby said annulus path can pass fluids before said sealing means have been extruded in said annulus,

means for extruding said sealing means in said annulus to effect a seal between said casing hanger mandrel and said tubular member, and

said setting tool having releasable means for anchoring said extruding means to said tubular member to permit driving said extruding means downward relative to said tubular member.

3. A casing hanger assembly for hanging a casing string in a tubular member having an upper groove and a lower shoulder therein, comprising in combination:

a casing hanger mandrel connectible. to the upper end of said casing string adapted to land on said lower shoulder, said mandrel being of a configuration such that an annular path is defined between said mandrel and said head through which path fluids can pass when said mandrel is landed on said lower shoulder of said head,

an extrudable packer arranged in said annulus to permit passage of fluids through said annular path before said packer is extruded,

a setting tool for extruding said packer in said annulus, and means for anchoring said setting tool in said upper shoulder.

4. The apparatus of claim 3 including a setting sleeve and means on said setting tool for driving said sleeve downwardly to set said packer in said annulus.

5. The apparatus of claim 4 including means for holding said setting sleeve in downward position relative to said casing hanger mandrel.

6. The apparatus of claim 4 including means cooperating with said setting sleeve and said casing hanger mandrel to hold said setting sleeve in downward position.

7. The apparatus of claim 4 including releasable means for anchoring said tool relative to said tubular member in said groove, and wherein a fluid chamber is defined between said driving means and said anchoring means, and means for applying fluid pressure to said chamber to thereby expand said chamber and move said driving means downward to set said packer.

8. An underwater casing hanger apparatus for hanging a casing in a wellhead having an upper groove and a lower shoulder therein and affixed to a formation underlying a body of water, comprising in combination:

a casing hanger mandrel connectible to the upper end of a casing string and having means thereon for landing said mandrel on said shoulder, said mandrel being so arranged and constructed that when landed on said shoulder, an annular path is defined between said mandrel and said head through which path fluids can pass,

extrudable packer means for sealing said annulus, said packer means being arranged in said annulus to permit fluid returns to pass through said annulus before said packer is extruded,

a shouldered sleeve arranged and constructed around said mandrel for extruding said packer in said annulus when said sleeve is moved downwardly,

a setting tool having means for anchoring said tool longitudinally in said groove as said setting tool is lowered into said head and registers axially with said groove,

hydraulic means for holding said anchor means in locking position and driving said sleeve downwardly to extrude said packer,

slip means for holding said sleeve in said downward position relative to said casing hanger mandrel,

a tubular member threadable on the upper end of said mandrel arranged and constructed for bearing against a shoulder on said setting sleeve to hold said setting sleeve in its downward position relative to said casing hanger mandrel when said tubular member is threaded downwardly to said sleeve shoulder after said sleeve is moved downward hydraulically, as aforesaid,

a first floating nut splined to said setting tool and threaded to said casing hanger mandrel arranged and constructed to support said mandrel on said setting tool as said tool is lowered into said head, said first floating nut being releasable from said mandrel when said tool is rotated,

an actuating sleeve including clutch means for engaging said tubular member,

a second floating nut threadable to said setting tool and splined to an actuating sleeve arranged and constructed to thread said tubular member downwardly to said sleeve shoulder as said setting tool is rotated,

a third floating nut threadable to said tool by left hand threads and splined to said anchor means so arranged and constructed that upon rotation of said setting tool to the right said setting nut moves downwardly to release said setting tool from said groove.

9. An underwater casing hanger apparatus for hanging a casing in a tubular member having an upper groove and a lower shoulder therein and affixed to a formation underlying a body of water, comprising in combination:

a casing hanger mandrel connectible to the upper end of a casing string and having means thereon for landing said mandrel on said shoulder, said mandrel being so arranged and constructed that when landed on said shoulder an annular path is defined between said mandrel and said tubular member through which path fluids can pass,

extrudable packer means for sealing said annulus, said packer means being arranged in said annulus to permit fluid returns to pass through said annulus before said packer is extruded,

a shouldered sleeve arranged and constructed around said mandrel for extruding said packer in said annulus when said sleeve is moved downwardly,

a setting tool having means for anchoring said tool longitudinally in said groove as said setting tool is lowered into said tubular member and registers axially with said groove,

means for holding said anchor means in locking position, means engaging said extruding sleeve and arranged and constructed to move said sleeve downwardly,

means for holding said sleeve in said downward position relative to said casing hanger mandrel,

disconnectible means for supporting said mandrel on said setting tool as said mandrel is lowered into said tubular member, and

means actuatable by rotationof said setting tool for releasing said anchor means so that said setting tool can be removed from said tubular member.

10. The apparatus of claim 9 including means for positively holding said setting sleeve in said downward position, said means being actuatable by rotation of said setting tool.

11.'A casing hanger apparatus for hanging a casing in a-wellhead having an upper groove and a lower shoulder therein, comprising in combination:

a casing hanger mandrel connectible to the upper end of a casing string and having means thereon for landing said mandrel on said shoulder, said mandrel being so arranged and constructed that when landed on said shoulder, an annular path is defined between said mandrel and said head through which path fluids can pass,

extrudable packer means for sealing said annulus, said packer means being arranged in said annulus to permit fluid returns to pass through said annulus before said packer is extruded,

a shouldered sleeve arranged and constructed around said mandrel for extruding said packer in said annulus when said sleeve is moved downwardly,

a setting tool having means for anchoring said tool longitudinally in said groove as said setting tool is lowered into said head and registers axially with said groove,

means for holding said anchor means in locking position, means engaging said extruding sleeve and arranged and constructed to move said sleeve downwardly, said last means communicating with the bore of said setting tool and defining a fluid chamber with said anchor holding means,

means for applying fluid pressure to said chamber to drive said sleeve downwardly,

means for holding said sleeve in said downward position relative to said casing hanger mandrel,

disconnectible means for supporting said mandrel on said setting tool as said mandrel is lowered into said head, and means actuatable by rotation of said setting tool for releasing said anchor means so that said setting tool can be removed from said head.

References Cited UNITED STATES PATENTS 20 JAMES A. LEPPINK, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,357,486 December 12, 1967 Cicero C. Brown It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 21, strike out "To provide a piston for the hydraulically setting packer" and insert instead T o actuate the hydraulic means a shoulder 86 is proline 51, strike out "in", first occurrence; column 6, line 49, for "allow" read allowing Signed and sealed this 15th day of April 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. IN AN UNDERWATER CASING HANGER ASSEMBLY FOR HANING A CASING STRING IN A TUBULAR MEMBER HAVING A SHOULDER THEREIN AND AFFIXED TO A FORMATION UNDERLYING A BODY OF WATER AND WHEREIN A CASING HANGER MANDREL CONNECTIBLE TO THE UPPER END OF SAID CASING STRING IS ADAPTED TO LAND ON SAID SHOULDER AND IS OF SUCH A CONFIGURATION THAT AN ANNULAR PATH IS DEFINED BETWEEN SAID MANDREL AND SAID TUBULAR MEMBER, AND WHEREIN ANNULAR SEALING MEANS ARE PROVIDED BETWEEN SAID MANDREL AND SAID MEMBER WHICH ARE OF A CONFIGURATION THAT PERMITS FLUIDS TO PASS SAID SEAL BEFORE SAID SEAL IS EXTRUDED IN SAID ANNULUS, THE IMPROVEMENT COMPRISING: 